diff --git a/main/redis/APKBUILD b/main/redis/APKBUILD
index 1a053488c93..213bc1c56e5 100644
--- a/main/redis/APKBUILD
+++ b/main/redis/APKBUILD
@@ -2,6 +2,7 @@
 # Contributor: Eivind Uggedal <eu@eju.no>
 # Maintainer: TBK <alpine@jjtc.eu>
 pkgname=redis
+# CAUTION: Do not upgrade to 7.3+ (non-free license).
 pkgver=7.2.4
 pkgrel=0
 pkgdesc="Advanced key-value store"